In a polishing apparatus, an optical connector polishing jig holds the MT ferrule provided at the connection end portion of the optical connector, the optical connector polishing jig includes: a cylinder base; a cylinder shaft held on the cylinder base to be capable of moving in the up-down direction; and a set block connected to an end of the cylinder shaft and having a hole into which the MT ferrule is inserted and in which fixing means for adjusting the pressing force and fixing the MT ferrule is inserted, and a surface of the fixing means that comes into contact with the MT ferrule has a protrusion that partially protrudes to apply a pressing force to the MT ferrule such that when the MT ferrule is fixed, an end surface of the MT ferrule is slightly deformed and a center portion of the end surface in a longitudinal direction swells.